Certain treatments require the temporary or permanent interruption or modification of select nerve function. One example treatment is renal nerve ablation, which is sometimes used to treat conditions related to congestive heart failure. The kidneys produce a sympathetic response to congestive heart failure, which among other effects, increases the undesired retention of water and/or sodium. Ablating some of the nerves running to the kidneys may reduce or eliminate this sympathetic function, which may provide a corresponding reduction in the associated undesired symptoms.
Many body tissues, such as nerves, including renal nerves, brain tissue, cardiac tissue and the tissue of other body organs, are in close proximity to blood vessels or other body cavities. This location enables the body tissues to be accessed percutaneously or intravascularly through the walls of the blood vessels. In some instances, it may be desirable to ablate perivascular nerves using a radio frequency (RF) electrode. In other instances, the perivascular nerves may be ablated by other means, including application of thermal, ultrasonic, laser, microwave, and other related energy sources to the vessel wall. The target nerves must be heated sufficiently to make them nonfunctional, however tissue adjacent to the nerves may also be damaged. It may be desirable to provide for alternative systems and methods for intravascular nerve modulation.